<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script src="js/jquery-3.3.1.min.js" type="text/javascript" charset="utf-8"></script>
		<script type="text/javascript">
			$(function () {
				$("button").click(function () {
					console.log("button")
				})
				
				$("select").change(function () {
					console.log($(this).val())
				})
				
				$("#txt").blur(function () {
					if($(this).val()==="")
					$(this).val("账号")					
				})
				$("#txt").focus(function () {
					if($(this).val()==="账号")
					$(this).val("")
				})
				
				//$("button").mousemove(function () {
				//	$(this).css("color","red")
				//})
				//$("button").mouseout(function () {
				//	$(this).css("color","green")
				//})
				//$("button").hover(function () {
				//	$(this).css("color","green")
				//},function () {
				//	$(this).css("color","green")
				//})
				
				$("#txt").on("click dblclick",function () {
					console.log(1)
				})
			})
		</script>
	</head>
	<body>
		<div class="div">
			<button type="button">点击</button>
		</div>
		<!--multiple多选  size显示个数-->
		<select name="" >
			<option value="1">中国</option>
			<option value="2">中国</option>
			<option value="3">中国</option>
		</select>
		<input type="text" name="" id="" value="" placeholder="111" />
		<input type="text" name="txt" id="txt" value="账号" />
		<input type="submit" name="" id=""  />
	</body>
</html>
